A gas turbine engine includes one or more forward compressor sections for increasing the pressure of an incoming air stream. For example, a turbofan jet engine includes a low pressure compressor (LPC) disposed between fan at the inlet of the engine and a high pressure compressor (HPC). Each compressor includes alternating axial stages of rotors and stators. Each stator is disposed within a circumferential case. Each rotor may include an outer ring of rotating blades; each stator may include a ring of stator segments, with each segment including a shroud connected to an individual vane or a shroud connected to a plurality of vanes. Each shroud may include forward and aft hooks for coupling the segment to the case. More specifically, each shroud may include a forward hook that is received in a forward slot of the case. Further, each shroud may include an aft hook that is received in an aft slot of the case or a pair of aft hooks that receive a forwardly extending tab of the case.
The case may be split into forward and aft portions. For example, during assembly, each segment is inserted axially into the case by inserting the aft hook(s) of each segment into the aft slot of the aft case portion. Then, when all of the segments are installed in the aft case portion, the forward portion of the case may be axially installed by inserting the forward hooks of the stator segments into the slot of the forward portion of the case.
One problem associated with the above-described stators is the potential for axial movement of the individual stator segments within the case when a load is imposed upon the stator assembly. See, e.g., U.S. Pat. No. 7,032,904. One way to avoid axial movement of the individual stator segments is to provide non-linear or non-straight side edges of the shrouds of the individual stator segments. The side edges may be shaped so that adjacent side edges of stator vane segments will fit together in a complementary manner. However, using non-linear side edges for the shrouds of the individual stator segments creates problems when axially inserting the individual stator segments into the case. Specifically, the last vane segment of each stator to be placed in the case may only be installed radially, not axially, due to interference with the side edges of the remaining stator segments. This is problematic because of the use of the forward and aft hooks to secure the stators to the case.
As a result, there is a need for an improved stator segment design that enables all stator segments to be inserted into an endless case axially as opposed to radially and in an efficient manner.